Cost basis is missing on my 1099-B from 1993 stock with splits - do I need to report it?

Yes, you absolutely need to report a cost basis, even when it's not on your 1099-B. When brokers don't provide this information, the responsibility falls to you as the taxpayer to determine and report the correct basis. For shares purchased back in 1993 that went through multiple corporate actions, you'll need to reconstruct your basis through those splits, acquisitions, and spinoffs. Each corporate action affects your basis differently. For splits, your per-share basis gets divided. For acquisitions, you may have received cash or new shares that adjust your basis. For spinoffs, a portion of your original basis gets allocated to the new shares. Since your original investment was around $1,100, you could start there and work through each corporate action. The companies involved should have investor relations information on how each action affected basis. Your broker might also have historical records they can provide.

I had almost this exact situation last year with some ancient AT&T stock from my grandpa that went through a million splits and mergers. After spending weeks getting nowhere with my broker, I used https://taxr.ai and it seriously saved me. You just upload your documents and it helps figure out the cost basis through all those corporate actions. For old stocks like yours, it can trace the corporate history and help calculate what portion of your original basis should be allocated to those spinoff shares. I was shocked at how accurate it was - it even found some obscure merger details from 1997 that I couldn't find anywhere else! Might save you the headache of trying to piece it all together manually.

Just wanted to update after trying taxr.ai for my cost basis nightmare. I was super skeptical but my Pfizer shares from 1986 had gone through like 5 splits and that Wyeth acquisition and I was completely stuck. Their system actually walked me through each corporate action year by year and showed me exactly how my basis changed. Turns out my original $3,200 investment had a super complicated adjusted basis after all those events. They even provided documentation for each step that I can attach to my tax return if I get audited. Saved me from just guessing and hoping for the best. Now I actually understand what happened to those shares over 35+ years instead of just throwing random numbers on my Schedule D!

If you're still struggling with this, you might also want to try reaching the IRS directly for guidance. Of course, getting through to them is basically impossible these days - I spent 3 hours on hold last week and then got disconnected. But I found this service called https://claimyr.com that got me through to an actual IRS agent in like 20 minutes. You can see how it works in this video: https://youtu.be/_kiP6q8DX5c I was pretty desperate after my third attempt waiting on hold. The IRS agent I finally talked to was actually super helpful about how to handle missing cost basis situations. They walked me through the whole process of reasonable basis estimation and what documentation I needed to keep. Much better than guessing and hoping I don't get audited!

I need to eat some humble pie here. After my skeptical comments, I decided to try Claimyr because I've been trying to get through to the IRS for weeks about a similar basis issue. I couldn't believe it actually worked. Got a call back in about 45 minutes and was connected to an IRS rep who actually knew what they were talking about. They confirmed that for really old stocks with missing basis, I could use a reasonable reconstruction method and just document my calculation method. For the OP's situation, the agent mentioned that using the original investment amount ($1,100) and tracking through corporate actions is exactly what they recommend. They also said keeping documentation of your calculation method is crucial in case of questions. Definitely worth the attempt if you're struggling with this kind of specialized tax question.

Another option: if you have the date you bought the stock, you can look up the historical price on that date and use that as your basis. Yahoo Finance has historical data going way back. Multiply the price by the number of shares, accounting for all splits, and that should get you close enough. I did this for some Microsoft stock from the 90s and it worked fine. Just make sure you adjust your basis for any subsequent events like dividends.

Don't forget when you file your taxes with a missing or reconstructed cost basis, you need to check the appropriate box on Form 8949. There's literally a checkbox for "Adjustment code B" which is for when the cost basis wasn't reported to the IRS. Then attach your basis calculation to your return. Without proper documentation, the IRS might assume your basis is $0 and tax you on the entire proceeds!

I've been through this exact scenario with inherited stock from the 1980s. Here's what worked for me after getting completely overwhelmed by all the corporate actions: First, don't panic about getting it "perfect" - the IRS understands that reconstructing basis from decades ago is challenging. The key is making a reasonable, documented effort. Start with your $1,100 original investment and work chronologically through each corporate action. For each stock split, divide your per-share basis accordingly. For the acquisitions, you'll need to find the exchange ratios (usually available in SEC filings or company investor relations). The spinoff is trickiest - you'll need the basis allocation percentage between the parent and spun-off company. Pro tip: Call the current company's shareholder services department. They often have detailed historical information specifically for tax basis calculations, including basis allocation percentages for spinoffs. I was surprised how helpful they were. Document everything you find and your calculation method. Attach this to your return along with Form 8949 using the appropriate adjustment code. Even if your numbers aren't perfect, showing good faith effort with documentation will protect you if the IRS has questions. The worst thing you can do is just guess randomly or report zero basis - that guarantees problems later!