I'm a 30+ year veteran of AT&T and, somewhere along the line, picked up shares of AT&T & Comcast, the latter probably from a spinoff at some point. The problem is, I have no idea of when I acquired these securities or their cost basis.

I'd now like to sell them.

Is my only recourse to declare all of the proceeds from the sale as a capital gain (i.e. as if the original purchase price was zero)?

Thanks for your help!

Somewhere along the line you acquired them OK--where are they now ? and who put them there. If I was to guess off the top of my head I'd say a matching 401k that the company put in stock--thern sometimes companies give you stock as a bonus for everybody or you get them when companies get bought out.---------Union pacific gave stock options good for 7 yrs if certain performance goals were met--all employees got them especially the former southern pacific employees. Even a dollar bill has a serial number, stocks have numbers too.I'd say you got years of pay stubs to go thru. Did you belong to a union that got a negotiated agreement from AT&T for stock ?? If so find the agreement, find the date of the agreement---and it makes a difference as to how you got it not just when you got it.

Let me splain the railroad deal.Union Pacific bought Southern Pacific 10 or so years ago. Big management shake up, SP managers and vice presidents out on the street jobless------but not the workers. Safety went to hell and the now Union Pacific stocks dropped big time. So UP came up with a deal for employees.If we met certain goals in say 2 years all employees would be given the option of buying 200 shares of stock at 55 dollars a share exercisable for like 8 years.If I waited I could have exercised my options for 125 a share.I exercised at 75----------now that was considered income, no long or short term gain-------flat income and I had to pay social security (railroad retirement) on it too--------so it makes a difference, when and how you got it and who gave it to you too----keep looking

Will do. Thanks for the response!