Time and again McCarthy came to the Royals' rescue by producing a succession of world-class saves to deny Luis Suarez, Steven Gerrard, Philippe Coutinho and Daniel Sturridge.
The academy product, who recently recovered from shoulder surgery, only started the match after Adam Federici was ruled out with an ankle problem.
Liverpool dominated most of the Barclays Premier League clash at the Madejski Stadium and could have finished clear winners but for McCarthy's brilliance.
Chance after chance went begging before the interval and apart from a bright spell from Reading midway through the second half when Noel Hunt and Jobi McAnuff could have scored, they were in full control.
The final 10 minutes saw Liverpool lay siege to the home goal and while Sturridge was guilty of butchering a match-winning opportunity, Suarez could only stare in disbelief as he was foiled by the terrific McCarthy twice in quick succession.
The draw halted Reading's run of seven successive Premier League defeats and while it may not prevent them from being relegated, the spirit on display will have been appreciated by manager Nigel Adkins.
A minute's silence was immaculately observed before the match in memory of the 96 victims of Hillsborough, with the disaster's 24th anniversary falling on Monday.
Liverpool made one change to the side that drew with West Ham, replacing Stewart Downing with Sturridge, and they were immediately into their stride as they passed their way through Reading with ease.
They would have taken the lead but for a brilliant clearance from right-back Chris Gunter, who scooped Suarez's lofted shot off the goalline as the home defence was split open with ease.
From early on it was clear Reading were leading a charmed life as McCarthy made a fine double save off Sturridge and Coutinho, while Jamie Carragher sent a corner whistling over the crossbar.
Shortly after rescuing his side with his goalline heroics, Gunter then blundered by passing straight to Sturridge who could scarcely believe his luck as he unleashed Suarez onto the Royals' goal.
But once more McCarthy reacted brilliantly to stop the shot before Gerrard's follow up was deflected over the target.
Carragher was forced to intervene in the nick of time as Reading attacked, but the respite was only brief as Liverpool countered and Coutinho should have done much better with a great chance.
The reflexes of McCarthy were all that was keeping the Reds at bay and he produced another magnificent save to deny Sturridge from close range.
Liverpool finally had the ball in the net three minutes into the second half, but the flag went up for offside against Coutinho as he dabbed Gerrard's pass home.
Frustration began to creep into Liverpool's play, born out of their inability to deliver the opener their ascendancy deserved.
Instead, Reading began to play a bigger role in the match and could have taken the lead in the 67th minute when Pavel Pogrebnyak played in Hunt only for Reina to throw his body in the way.
Danny Guthrie then saw a shot blocked while at the other end the wasteful Coutinho blasted a fine pass from Sturridge well wide of the right post.
Now the match was anyone's and in the 65th minute Reading would have taken the lead had McAnuff struck the ball with greater force from 10 yards out, with the weakness of the shot allowing Reina to parry it clear.
Suarez and Downing then went close, and then it was Gerrard's turn to be denied by the fingertips of McCarthy.
Somehow, McCarthy then plucked a shot from Suarez from the air and palmed another attempt from the Liverpool forward to safety, while Sturridge blazed high over the crossbar.