14-Day Best of the Adriatic

It depends on how often and what you plan on using your phone for. I pretty much use wifi when in Europe. I download Ulmon offline maps for the cities I am visiting and use those as well as paper maps when doing my planning. If you plan on using your phone to make multiple calls for reservations and such, then buying a sim card to use over there would be better than paying Verizon $10/day imo. Some people are willing to eat the cost of the Verizon plan, figuring they are already spending thousands on the trip. That makes sense.
Another option that Verizon has is the $40 plan - 100 minutes of calling, 100 texts (in and out), and a piddly 100 mb of data.
If you do decide to change your sim card when you get there make sure you put it somewhere very safe so you can put it back in when you come home.

If you can, try to arrive a day or two early for the tour (and reserving the same tour hotel for those extra nights works well for me) to acclimate and recover from jet lag. Ljubljana is definitely worth the extra days. I really fell in love with the city. The tour is amazing, educational, full of natural wonders and wonderful experiences. I loved every minute of it; so much so that I am thinking seriously about taking my adult children and practically adult grandchildren on it during the summer of 2019. It was very warm in Mostar when we were there (early May) but weather is so variable, that means practically nothing! Other than that, our weather was outstanding. I bet you'll enjoy the heck out of your tour. To answer your phone question: I had/have an iPhone with TMobile as my provider. I had no issues and no charges other than my monthly fee with the plan I have. Someone on here can explain better than I what the GSM card is and how to use it!

We have used the Verizon $40/ 30 day charge and it works fine for us. We must remember to turn off all data when we do not need it or those apps with updates can eat up your limited data allowed, but don't worry for another fee ($25, I think) they'll add more data. When with a group we rarely ever needed to use the phones, so we did most of our updating, checking on family, etc when in the free wifi at the hotels. We went on that tour in fall of 2016 and had no trouble. I agree, download the maps from either the group the other responder mentioned or from googlemaps ahead of leaving your highspeed wifi at home. It was fun to see where the bus was going all offline. (your gps will still work).

Every time you cross a border Verizon will text you (a free text) to welcome you into the next country.. sort of cool.
We would not pay the $10/ day deal.. just don't need that much data or calls. And we are much to lazy to hunt up a place to by a SIM card and have any problems with it. Plus I understand calls back to the usa do cost? (not sure on that one)
You tell Verizon exactly what day you are leaving.
You'll enjoy the Adriatic tour and I would also advise to get there a day early. Ljubljana is a great city. We booked a viator tour to one of the caves on the day before the trip started... It was great, wish a cave was included in the RS tour. Happy travels.

I think you may want to spend sometime to determine your needs. So will you be calling? Home or to hotels, restaurants, etc. texting? Email and general web surfing or mapping? Perhaps all of the above.
Will keeping a US number be important?

Depending on your needs wifi may suffice, but perhaps sign up for the $10 daily plan as a backup.

I’ve purchased a local SIM card with plans good for 30 days. It’s worked well for me. But it does mean that I get a British or Italian phone number. Not a big deal for me. It’s fairly cheap bet €25 and £17. I don’t need to find WiFi when I do something on the run and it’s nice to have when the Hotel WiFi isn’t usable (about 15% of the time in my experience).

Here’s a recent thread that has much more info, perhaps too much.

https://community.ricksteves.com/travel-forum/tech-tips/complicated-phone-needs-abroad

Andrew H created this thread las fall that details how to get a Vodafone SIM card before you leave.

https://community.ricksteves.com/travel-forum/tech-tips/dutch-vodafone-sim-card-for-use-in-europe

I don’t believe that Verizon locks smartphones anymore but it’s best to check with them. An unlocked phone is required when going the local SIM card route.

Thanks for all the helpful information. I need all I can get :-D

I am NOT a techie, so I am easily confused. How does using wi-fi affect the use of my phone data? If I Google some info or get on my email using wi-fi, does that affect my phone data/use/charges?

Rocket, Thanks for the link to "complicated phone needs." I was in that very position 3 years ago and unfortunately didn't have access to that kind of information. One of the great benefits of going on an RS tour. The rest of the thread was quite helpful, so I will check into some of those things suggested. Thank you!

If you are on WIFI, you are not using any of your phones data. When I go to Europe I put my phone in airplane mode and leave it there. If I am at a hotel/restaurant, etc that provides WIFI, then I can connect using that for free to check mail or make calls using Skype. Otherwise I just don't connect or make calls.

Be warned-last summer we thought I was getting the $40/30 days service from Verizon and they charged us the $10/day instead. No way to prove since there was no paper trail. Have since switched to a cheaper provider.

I really don't talk much on the phone but to my wife. And she travels with me.
Last year, my T Mobile international plan cut off after 2 calls in The Azores and their customer no service in the Philippines was like talking to a brick wall. I immediately cancelled my service and communicated just fine on Wi-Fi at my hotels. And my tablet was free to use.

One of the links from "complicated phone service" said you could use Google Hangouts. My only real need is to be able to contact my hubby from time to time, since he can't travel right now. We both have that on our phones. That sounds like a free service as long as I use wi-fi and I'm the one initiating the message. Is that correct info? Does it depend on your carrier? From your responses, it sounds like if I'm on wi-fi with my iPad or my android phone, there would be no charges.

I'm sorry to be such a bother, but I've really lost touch with all the technology and I want to be clear before I leave. Thank you all so much for the VERY helpful info and direction.

Roberta, since you gave Verizon and a Samsung Galaxy, you can enable your phone for WiFi calling and while you are on WiFi, it is no additional cost. Here are the instructions: https://www.verizonwireless.com/support/knowledge-base-203686/
Nothing to download, no new number and you can call anyone in the US and they can call you no charge.
I keep my phone on airplane mode and wait till I am on WiFi to make calls or send texts when on WiFi. I also get the Verizon $40 a month plan for 100 minutes of calling, 100 texts to send, I can receive texts for free and 100 mb of data. I only use it for calls in country, not for calls to the US. After I sign up for it I make sure I get a confirmation email about the change in plan.

roberta,

I'm not too familiar with the plans offered by U.S. cell networks, but a few thoughts.....

I've taken the RS Adriatic tour and on that trip I was using a SIM with O2 (UK). I kept the cellular data switched off unless I needed it for some reason, and that worked reasonably well. However I found that the service was erratic in some areas and I haven't been able to figure out why that was? At times it would show normal service and then a few minutes later, no service for either data or calls / texts.

On trips since then, I've been using the Roam Like Home plan with my home network and have found that very reliable so far. It's expensive but by far the easiest and simplest method. There's a cost for the convenience though. I have to be available from home, so that precludes me from using a SIM purchased in Europe which would have a different number, and for me a different SIM would be more of a hassle.

One advantage I've found with using roaming with my home cell network is that the phone is able to change providers as I wander about Europe. If one European network has weak coverage in one area, my phone will roam onto a different network. I'm not sure, but suspect the phone looks for the strongest signal. That wouldn't happen if using a SIM purchased with a specific European network.

Good luck!